Brush tool for cleaning downhole tubular bore

ABSTRACT

An elongate brush tool for cleaning a bore of a tubular comprising a first end, a second end, a body between the ends, a plurality of necked channels in an radially exterior portion of the body, each necked channel having a proximal end with an opening, a distal end having a stop, a slot between the proximal end and the distal end, and a channel closure member removable securable to the body, and further comprising a plurality of brush elements, each having a head and a plurality of bristles forming a bundle extending from the head, the brush element head being sized for being received through an opening, of a necked channel and into the necked channel with the bundles received within the slot. A plurality of channel closure members prevent removal of the head of the brush elements from the necked channel during use of the brush tool.

BACKGROUND

1. Field of the Invention

The present invention relates to a brush tool for cleaning a tubular bore such as, for example, a downhole tubular bore or a pipeline. More specifically, the present invention relates to a brush tool for cleaning a tubular bore that comprises a plurality of replaceable brush elements.

2. Background of the Related Art

Oil and gas is generally recovered from geologic formations in the earth's crust by drilling a wellbore from the earth's surface into the earth's crust and by running a tubular string into the wellbore to access and recover fluids residing in one or more geologic formations penetrated by the wellbore. A variety of materials may adhere to the interior bore wall of the tubular string including, but not limited to, mud cake, cement and other materials. It is critical to maintain a full and clean bore to enable the unimpaired movement of packers and other tools that are sized for being installed through the bore of the tubular string.

Tools have been made for being run into the bore of the tubular string to remove adhered materials from the interior bore wall of the tubular and to thereby restore bore clearance for the movement of packers or other tools through the bore to the intended location. These tools may include brush elements such as, for example, wire bristles that are sufficiently rigid to abrade, dislodge and remove materials adhered to the interior bore wall of a tubular string to be cleaned using the tool.

BRIEF SUMMARY

One embodiment of the present invention provides a brush tool comprising an elongate body having a center axis, a first connector at a first end, a second end, and a plurality of necked channels formed in a radially outwardly exterior portion of a brush section of the body, each necked channel having an opening at a proximal end and a stop at a distal end, each necked channel having a slot extending from proximal to the opening to proximal to the stop, and each necked channel extending angularly about at least a portion of the body from the proximal end of the necked channel about the center axis of the body to the distal end of the necked channel, the brush tool further comprising a plurality of brush elements, each brush element having an enlarged head that is larger than the slot of the necked channel in which the brush elements are adapted to be retained. The enlarged heads of the plurality of brush elements are sized to be received through the opening of a necked channel into the necked channel. Each brush element includes a bundle of bristles with each bristle having a proximal end secured to the enlarged head of the brush element and a distal end extending outwardly from the enlarged head. The bundle of bristles of each brush element are sized for being received into the slot of the necked channel as the head of the brush element is laterally received into the opening of the necked channel. The brush tool of the present invention further comprises a plurality of channel closure members, each channel closure member securable to the body of the brush tool at a location that is proximal to the opening of a necked channel to block the heads of a plurality of brush elements from being removed from the necked channel. Each of the plurality of brush elements are laterally receivable within and securable within one of the plurality of necked channels of the body of the brush tool by laterally receiving the enlarged head of each of the brush elements through an opening of a necked channel and into the necked channel and by laterally receiving the plurality of bristles of the brush element into the slot of the necked channel, and by securing a channel closure member to the body proximal to the opening.

One embodiment of the brush tool further comprises a second connector at the second end. In one embodiment, the first connector and the second connector each comprise a threaded and tapered connection. In one embodiment, the brush tool comprises a throughbore extending from the first connector at the first end to the second connector at the second end.

Another embodiment of the brush tool comprises necked channels wherein each necked channel includes a proximal end axially displaced along a portion of the center axis of the body from a distal end. Another embodiment of the brush tool comprises necked channels wherein each necked channel includes a proximal end angularly displaced about the center axis from a distal end. Another embodiment of the brush tool comprises necked channels wherein each necked channel includes a proximal end that is axially displaced along a portion of the center axis and angularly displaced about the center axis from the distal end. This embodiment includes necked channels that follow a segment of a spiraling path about the center axis of the brush tool.

One embodiment of the brush tool of the present invention comprises a plurality of brush elements wherein each brush element includes a bundle of bristles formed by bunching the bristles together at a first end of each bristle and wherein in the second ends of the bristles coextend. The first ends of the plurality of bristles may be secured within the enlarged head of the brush element using a compression fit, an adhesive, a bonding, agent, or by fusing or welding the first ends of the plurality of bristles together within the enlarged head of the brush element.

One embodiment of the brush tool includes a plurality of necked channels wherein each necked channel, can accommodate the enlarged heads of a set of four or more brush elements. It will be understood that the number of brush elements that can be accommodated in a necked channel is determined by the size of the enlarged head of the brush elements and the overall length of the necked channel formed on the brush tool between the opening, at the proximal end of the necked channel, and the stop, at the distal end of the necked channel.

One embodiment of the brush tool includes a plurality of necked channels disposed within a brush section of the brush tool wherein the number of necked channels in the exterior portion of the body of the brush tool is at least five.

One embodiment of the brush tool of the present invention comprises a plurality of necked channels wherein the necked channels on the body are in an axially spaced arrangement along the center axis of the body.

One embodiment of the brush tool of the present invention comprises a plurality of channel closure members securable to the body to close the openings of the plurality of necked channels wherein the channel closure member is a threaded channel closure member, and wherein the body further comprises a threaded aperture disposed proximal to the opening of a necked channel of the body to receive a threaded channel closure member therein to obstruct removal of an enlarged head of a brush element that has been laterally received through the opening and into the necked channel prior to receiving the threaded channel closure member into the threaded aperture. In one embodiment of the brush tool of the present invention, a threaded channel closure member is one of a screw and a bolt.

One embodiment of the brush tool of the present invention includes one or more alternate channel closure members securable to the body of the brush tool to close the openings of the necked channels of the body wherein each channel closure member comprises a bifurcated sleeve including a first sleeve half having a threaded aperture therein, a second sleeve half having an aperture that aligns with the threaded aperture of the first sleeve half upon securing the first sleeve half and the second sleeve half in a closed configuration about the body to together surround the central axis of the body and to obstruct removal of enlarged heads of brush elements from at least one necked channel on the body of the brush tool, and a threaded fastener sized for being received through the aperture of the second sleeve half to engage threads thereon with the threaded aperture of the first sleeve half to secure the channel closure member to the body of the brush tool. In one embodiment of the brush tool, the first sleeve half has an exterior surface, the second sleeve half has an exterior surface, and the exterior surfaces of the first sleeve half and the second sleeve half together align with an adjacent exterior surface of the body of the brush tool upon securing the channel closure member to the body of the brush tool. In another embodiment of the brush tool, the first sleeve half has an exterior surface, the second sleeve half has an exterior surface, and the exterior surfaces of the first sleeve half and the second sleeve half together form a radially extending plurality of lobes to maintain a minimum spacing between the center axis of the brush tool and an interior wall of a bore of a tubular string to be cleaned using the brush tool. This alternate closure member may be used to prevent unwanted deformation of the bristles of the brush elements retained within necked channels of the brush tool. In another embodiment of the brush tool, the first sleeve half has an exterior surface, the second sleeve half has an exterior surface, and at least one of the exterior surfaces of the first sleeve half and the second sleeve half includes a necked channel having a proximal end proximal to an opening of the necked channel and a distal end distal to the opening of the necked channel and proximal to a stop. This alternate channel closure member serves the dual purposes of securing a plurality of brush elements within a necked channel in the exterior portion of the body of the brush tool disposed adjacent to the alternate channel closure member while also providing an additional necked channel on at least one of the first sleeve half and the second sleeve half to receive and retain additional brush elements.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a brush tool of the present invention adapted for being connected to a workstring and run into a bore of a tubular string for cleaning the interior wall of the bore of the tubular.

FIG. 2 is a perspective view of an alternate embodiment of the brush tool of the present invention having, alternative channel closure members for securing a plurality of brush elements in adjacent necked channels.

FIG. 3 is an end view of the brush tool of FIG. 1.

FIG. 4 is an elevation view of a brush element having an enlarged head removably securable within a necked channel of embodiments of the brush tool of the present invention.

FIG. 5 is a sectional view of a necked channel of an embodiment of a brush tool of the present invention that laterally receives and removably secures a plurality of the brush elements of FIG. 4 to an embodiment of a brush tool of the present invention.

FIG. 6 is an enlarged view of a portion of the brush tool of FIG. 1 revealing an opening to a necked channel on the body of the brush tool and a channel closure member closing the opening.

FIG. 7 is an end view of another alternate channel closure member that also serves as a stabilizer to maintain the center axis of the brush tool at a minimum separation distance from an interior wall of a tubular bore to be cleaned using the brush tool.

FIG. 8 is the perspective view of the brush tool of FIG. 2 with the alternate channel closure member of FIG. 7 substituted for the alternate channel closure members of FIG. 2.

FIG. 9 is a perspective view of another alternate channel closure member having necked channels formed thereon for laterally receiving the enlarged heads of additional brush elements.

FIG. 10 is the perspective view of the brush tool of FIG. 8 with the alternate channel closure members of FIG. 8 replaced with the alternate channel closure members of FIG. 9.

DETAILED DESCRIPTION

Embodiments of the brush tool of the present invention may be used to clean the interior bore wall of a tubular string such as a casing string through which tools may pass for being set at a targeted interval of the wellbore. Some embodiments of the brush tool of the present invention are adapted for repeated use and include replaceable brush elements. Other embodiments of the brush tool are adapted for a single use and may be left in the well, such as in a plug and abandonment operation. The enlarged head of each of a plurality of brush elements can be laterally received through an opening of a necked channel and retained in the necked channel formed on the radially exterior portion of the body of the brush tool, and then secured within the necked channel using a channel closure member to obstruct removal of the brush element from the necked channel. In embodiments adapted for repeated use, the enlarged head of each brush element can be removed from the necked channel after use and replaced with new or reconditioned brush elements.

In some embodiments, alternate channel closure members may be used to secure the enlarged heads of a plurality of brush elements in a necked channel formed in the exterior portion of the body of the brush tool. In one embodiment, the alternate channel closure member may itself include one or more additional necked channels to increase the capacity of the brush tool to receive and secure additional brush elements.

In one embodiment, an alternate channel closure member may be used to secure the enlarged heads of the plurality of brush elements in a necked channel formed in the exterior portion of the body of the brush tool, and the alternate channel closure member includes a plurality of radially outwardly extending lobes to provide a minimum separation distance between the center axis of the brush tool and the interior wall of the bore of the tubular string to be cleaned using the brush tool.

It will be understood that brush elements used in brush tools are likely to be worn, bent or otherwise compromised by abrasive engagement with the interior wall of a tubular bore cleaned using the brush tool. In embodiments of the brush tool of the present invention adapted for repeated use, the necked channels, closure members and brush elements of the present invention provide for rapid and convenient installation and removal of brush elements, which saves valuable rig time. In addition, the brush elements securable to embodiments of the brush tool of the present invention can be installed and removed with minimal tooling and with minimal labor.

The use of necked channels formed into the radially exterior portion of the body of embodiments of the brush tool enable a brush tool of a given diameter to have greater flow capacity of a throughbore that extends along the center axis of the brush tool and which can be used to transfer fluid through the throughbore of the brush tool. It will be understood that the securing of brush elements to a brush tool consumes an amount of radial space, depending on how the brush elements are secured to the brush tool. The necked channels of the brush tools of the present invention also consume less radial space and thereby allow a greater portion of the brush tool to be used for structural strength and brush tool loading capacity.

FIG. 1 is a perspective view of an embodiment of a brush tool 10 for being connected in a workstring (not shown) and being run from a rig into the bore of a tubular string in a well (not shown) for cleaning the interior wall of the bore of the tubular string. The brush tool 10 of FIG. 1 comprises an elongate body 26, a first connector 36 at a first end 12 of the tool 10 and an optional second connector 39 at a second end 14 of the tool 10.

A center axis 11 extends through the first connector 36, the body 26 and the second connector 39 of the brush tool 10 illustrated in FIG. 1. The first connector 36 of the embodiment of the brush tool 10 shown in FIG. 1 is adapted for threadably coupling the tool 10 to workstring. The first connector 36 includes a threaded hole 38 to threadably receive a pin end (not shown) of a tubular joint of a workstring (not shown). It will be understood that the first connector 36 would be structured differently for coupling an embodiment of the brush tool 10 of the present invention to a wire line or a slick line. It will be further understood that an embodiment of the brush tool 10 of the present invention adapted for being coupled to a workstring may include a throughbore extending from the first end 12 of the brush tool 10 through to the second end 14 of the brush tool 10 to accommodate fluid flow through the workstring (not shown) and the brush tool 10.

Other embodiments of the brush tool 10 of the present invention may be adapted for being moved through a bore of a tubular string using a plug, for example, a cementing plug, that can be coupled to the brush tool 10 and moved through the bore of a tubular string using fluid pressure applied to a trailing side of the plug to move the plug and the brush tool 10 through an interior bore of the tubular string and in the direction of the leading side of the plug. Embodiments of the brush tool 10 illustrated in the appended drawings should not be considered as limiting of the types of connectors that can be used on embodiments of the brush tool 10 of the present invention.

The tool 10 of FIG. 1 further comprises an elongate brush section 16 disposed between the first end 12 and the second end 14 of the brush tool 10. The brush section 16 of the brush tool 10 includes a plurality of sets 20 of brush elements 22, each set 20 of brush elements 22 is secured within one of a plurality of necked channels 27 disposed within the brush section 16 of the body 26 and within a radially exterior portion 24 of the body 26 to receive and retain the sets 20 of brush elements 22. The brush elements 22 within a set 20 are retained in a necked channel 27 in a generally curved configuration, as illustrated in FIG. 1, or in a different configuration dictated by the path of the necked channel 27 on the exterior portion 24 of the brush section 16 of the body 26 of the brush tool 10.

The necked channels 27 in the body 26 of the brush tool 10 in FIG. 1 each includes a component that extends circumferentially about the center axis 11 of the body 26 and also axially along the center axis 11 of the body 26. It will be understood that necked channels 27 of other embodiments of the brush tool 10 may lack either a circumferential component, meaning that the necked channel 27 has no circumferential component about the center axis 11 and extends in a straight line that is parallel to the center axis 11, or an axial component, meaning that the necked channel 27 has no axial component along the center axis 11 and wraps about the same point of the center axis 11 to form an arc. The preferred embodiment of the brush tool 10 of the present invention is illustrated in the appended drawings and includes necked channels 27 that have a spiraling or helical path about the center axis 11 which includes both circumferential and axial components.

In the embodiment of the brush tool 10 of FIG. 1, the body 26 extends from the first end 12 of the brush tool 10 to the second end 14 of the brush tool 10. Each necked channel 27 within the brush section 16 of the brush tool 10 of FIG. 1 is illustrated as having laterally received a set 20 of brush elements 22, each set 20 comprising a plurality of brush elements 22. Each set 20 of brush elements 22 secured to the brush tool 10 of FIG. 1 comprises an enlarged head that is laterally received into the necked channel 27 and secured within the necked channel 27 with bundles 45 of bristles 46 (bristles 46 not shown in FIG. 1—see FIG. 4) of the brush elements 22 extending, radially outwardly from the necked channel 27 through a slot 29 of each of the necked channels 27. Each set 20 of brush elements 22 are secured within a necked channel 27 by a channel closure member 28, for example, a bolt, secured to the body 26 of the brush tool 10 proximal to an opening 58 (not visible in FIG. 1—see FIG. 4) to prevent removal of the brush elements 22 from the necked channel 27.

FIG. 2 is a perspective view of an alternate embodiment of the brush tool 10 of the present invention having alternative channel closure members 33 for securing a set 20 of the brush elements 22 within each of the necked channels 27 formed in the body 26 of the brush tool 10. Each of the channel closure members 33 of FIG. 2 includes a first sleeve half 30 having a plurality of threaded apertures therein (not shown in FIG. 2) and a second sleeve half 31 having a plurality of apertures 32 therein that are aligned with the threaded apertures (not shown) of the first sleeve half 33. The alternate channel closure members 33 further comprise threaded fasteners 34, such as screws, received through the apertures 32 of the second sleeve half 31 and threadedly received into the threaded apertures (not shown) within the corresponding first sleeve half 30. It will be understood that, upon securing the first sleeve half 30 to the second sleeve half 31 using threaded fasteners 34 to form the alternate channel closure member 33, an edge 35 of the alternate channel closure member 33 will obstruct the opening 58 (not shown in FIG. 2—see FIG. 6) of each of the necked channels 27 of the brush tool 10.

FIG. 3 is an end view of the brush tool 10 of FIG. 1. FIG. 3 shows the threaded hole 38 of the first connector 36, the throughbore 37, the body 26 and the sets 20 of brush elements 22 extending radially outwardly from the body 26 of the brush tool 10. The necked channels 27 that laterally receive and secure the brush elements 22 are not visible in FIG. 3.

FIG. 4 is an elevation view of a brush element 22 that is removably securable to the brush tool 10 (not shown) of the present invention. The brush element 22 includes an enlarged head 44 having a width 43 and a depth 41. The enlarged head 44 receives and secures a proximal end 42 of a plurality of bristles 46 that together make up a bundle 45 of bristles 46. The distal ends 47 of the plurality of bristles 46 of the brush element 22 of FIG. 4 are coextensive. The enlarged head 44 of the brush element 22 of FIG. 4 may, in one embodiment, be round, so that the width 43 is a diameter, or the enlarged head 44 may be rectangular. The necked channels 27 of the brush tool 10 are may be adapted to accept brush elements 22 having different shapes and configurations.

FIG. 5 is a sectional view of a necked channel 27 that laterally receives and removably secures a set 20 of brush elements 22 (not shown in FIG. 5) such as, for example, a set 20 comprising a plurality of the brush element 22 of FIG. 4, to the brush tool 10. FIG. 5 reveals the necked channel 27 as including a slot 55 of the necked channel 27 through which the bundles 45 of the brush elements 22 (not shown in FIG. 5—see FIG. 4) protrude when a set 20 of brush elements 22 are laterally received into the necked channel 27. The slot 55 is formed between a first protruding leg 51 and a second and opposed protruding leg 52 in the body 26 of the brush tool 10. The necked channel 27 of FIG. 5 has a depth 54 that exceeds the depth 41 of the enlarged head 44 of the brush element 22 of FIG. 4, and the necked channel 27 of FIG. 5 has a width 53 that exceeds the width 43 of the enlarged head 44 of the brush element 22 of FIG. 4. These dimensions allow for slidable movement of the enlarged head 44 of a brush element 22 after it is laterally received into an interior 50 of the necked channel 27.

FIG. 6 is an enlarged view of a portion of the brush section 16 of the body 26 of the brush tool 10 of FIG. 1 to better reveal an opening 58 to one of the plurality of necked channels 27 on the body 26 of the brush tool 10. The opening 58 is sized and configured to laterally receive the enlarged heads 44 of a set 20 of the brush element 22 shown in FIG. 4. A channel closure member 58 such as, for example, a bolt having an alien wrench head, is secured to the body 26 of the brush tool 10 after the enlarged heads 44 of a set 20 of brush elements 22 are laterally received through the opening 58 and into the necked channel 27 with the bundles 45 of bristles 46 extending through the slot 55 of the necked channel 27. The channel closure member 58 is secured to the brush tool 10 to obstruct the removal of the enlarged heads 44 of the brush elements 22 from the necked channel 27 with the channel closure member 28.

FIG. 7 is an end view of an alternate channel closure member 60 that also serves as a stabilizer to maintain a center axis 11 of the body 26 of the brush tool 10 (not shown) at a minimum separation distance from an interior wall of a tubular bore (not shown). The alternate channel closure member 60 comprises a first sleeve half 61 having an aperture 68 and a threaded aperture 66, and a second sleeve half 62 with an aperture 68 and a threaded aperture 66. Upon assembly, as shown in FIG. 7, to surround and to be secured to the body 26 of the brush tool 10 (not shown), the aperture 68 of the first sleeve half 61 aligns with the threaded aperture 66 of the second sleeve half 62, and the aperture 68 of the second sleeve half 62 aligns with the threaded aperture 66 of the first sleeve half 61. It will be understood that threaded fasteners 69 can be received through the apertures 68 and into the aligned threaded apertures 66 to engage threads 65 on the fasteners 69 with corresponding threads 65 within the threaded apertures 66 of the first sleeve half 61 and the second sleeve half 62 to secure the first sleeve half 61 to the second sleeve half 62 and to secure the alternate channel closure member 60 of FIG. 7 onto the body 26 of the brush tool 10 of FIG. 2 in the place of the plurality of channel closure members 30 of FIG. 2. The radially protruding stabilizer lobes 63 on the first sleeve half 61 and the second sleeve half 62 may vary from one alternate channel closure member 60 to another to vary the “stand-off” or separation distance between the center axis 11 and the interior bore wall of the tubular string provided by the alternate channel closure member 60 of FIG. 7.

The resulting modified version of the brush tool 10 would appear as depicted in FIG. 8, which shows an embodiment of a brush tool 10 after substitution of a plurality of the alternate channel closure members 60 of FIG. 7 for the channel closure members 33 of FIG. 2. The alternate channel closure members 60 are installed onto the body 26 of the brush tool 10 of FIG. 2 using fasteners 69. The substitution of the alternate channel closure members 60 of FIG. 7 to provide the brush tool 10 shown in FIG. 8 will cause the stabilizer lobes 63 to maintain the center axis 11 of the brush tool 10 a minimum distance from an interior wall of a tubular bore to be cleaned using the brush tool 10. In the configuration illustrated in FIG. 8, the brush tool 10 is better adapted for cleaning the interior bore of a tubular that is at an angle to vertical, such as a highly inclined or horizontal portion of a wellbore. The alternate channel closure member prevents the bundles 45 of bristles 46 of the brush elements 22 on one side of the brush tool 10 from excessive bending under the weight of the brush tool 10 coming to bear on one side of the brush tool 10, as occurs in highly deviated or horizontal sections of a wellbore. It will be understood that the girth of the alternate channel closure members 60 across opposing stabilizer lobes 63 may be selected based on the length of the bristles 46 of the brush elements 22.

FIG. 9 is a perspective view of another alternate channel closure member 70 having necked channels 27 formed thereon for laterally receiving the enlarged heads 44 of additional brush elements 22 (not shown in FIG. 9) through the openings 58 and into the necked channels 27. It will be understood that the alternate closure member 70 of FIG. 9 secures onto the body 26 of the brush tool 10 in the same manner as described above for the channel closure members 33 and 60 illustrated in FIGS. 2, 7 and 8.

FIG. 10 is the perspective view of the brush tool 10 of FIGS. 2 and 8 with the alternate channel closure members like that illustrated in FIG. 9 substituted for the alternate channel closure members 33 of FIG. 2 and the alternate channel closure members 60 of FIG. 8.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components and/or groups, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.

The corresponding structures, materials, acts, and equivalents of all means or steps plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but it is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. 

What is claimed is:
 1. A brush tool, comprising: an elongate body having a center axis, a first end, a second end, and a plurality of radially outwardly necked channels fanned in a radially exterior portion of the body, each necked channel having an opening at a proximal end and a stop at a distal end, each necked channel having a slot extending from the opening to the stop, and each necked channel extending circumferentially from the proximal end and about the center axis of the body to the distal end; a plurality of brush elements, each brush element having an enlarged head that is larger than the slot of each necked channel and sized to be laterally received through the opening of a necked channel into the necked channel, and a plurality of bristles, each bristle having a proximal end secured to the head and a distal end extending outwardly from the head, the plurality of bristles of each brush element being positioned relative to the head for being laterally received into the slot of a necked channel as the head of the brush element is being laterally received into the opening of the necked channel; and a plurality of channel closure members, each channel closure member securable to the body proximal to the opening of a necked channel to block the heads of a plurality of brush elements from being removed from the necked channel; wherein each of the plurality of brush elements is securable within one of the plurality of necked channels of the body by receiving the head of the brush elements through an opening of a necked channel and into the necked channel and by receiving the plurality of bristles of the brush element into the slot of the necked channel, and by securing a channel closure member to the body proximal to the opening.
 2. The brush tool of claim 1, further comprising: a second connector at the second end.
 3. The brush tool of claim 1, wherein each necked channel includes having the proximal end axially displaced along a portion of the center axis of the body from the distal end.
 4. The brush tool of claim 1, wherein each brush element comprises a bundle of bristles formed by securing the proximal ends of the plurality of bristles one to the others; and wherein the distal ends of the bristles coextend.
 5. The brush tool of claim 1, wherein each necked channel is of sufficient length to accommodate four or more brush element heads.
 6. The brush tool of claim 1, wherein the number of necked channels on the body exceeds four.
 7. The brush tool of claim 1, wherein the necked channels on the body are in an axially spaced arrangement along the center axis of the body.
 8. The brush tool of claim 1, wherein the channel closure member is a threaded channel closure member; and wherein the body further comprises a threaded aperture disposed proximal to the opening of a necked channel of the body to receive a threaded channel closure member therein to obstruct removal of a brush element head received through the opening and into the necked channel prior to receiving the threaded channel closure member.
 9. The brush tool of claim 8, wherein the channel closure member is one of a screw and a bolt.
 10. The brush tool of claim 1, wherein the channel closure member is a bifurcated sleeve including a first sleeve half having a threaded aperture therein, a second sleeve half having an aperture aligned with the threaded aperture of the first sleeve half upon securing the first sleeve half and the second sleeve half in a closed configuration on the body to surround the central axis of the body and to obstruct removal of brush element heads from at least one necked channel on the body.
 11. The brush tool of claim 10, further including a threaded fastener sized for being received through the aperture of the second sleeve half to engage threads thereon with the threaded aperture of the first sleeve half to secure the channel closure member to the body of the brush tool.
 12. The brush tool of claim 10, wherein the first sleeve half has an exterior surface, the second sleeve half has an exterior surface, and the exterior surfaces of the first sleeve half and the second sleeve half together align with an adjacent exterior surface of the body of the brush tool upon securing, the channel closure member to the body of the brush tool.
 13. The brush tool of claim 1, further comprising: a stabilizer portion for maintaining about the center axis of the body of the brush tool a minimum radial distance of the center line from an interior bore wall of a tubular in which the brush tool is inserted.
 14. The brush tool of claim 13, wherein the stabilizer portion comprises a channel closure member including a first sleeve half having a threaded aperture therein, a second sleeve half having an aperture aligned with the threaded aperture of the first sleeve half upon securing the first sleeve half and the second sleeve half in a closed configuration on the body to surround the central axis of the body and to obstruct removal of brush element heads from at least one necked channel on the body.
 15. A brush tool, comprising: an elongate body having a first connector at a first end, a second end, a throughbore along a center axis of the body to permit fluid flow through the brush tool, and a plurality of necked channels in a radially exterior portion of the body, each necked channel having a distal end, a proximal end, a slot and an opening proximal to the proximal end; a plurality of channel closure members securable to the body proximal to the opening of each of the plurality of necked channels; a plurality of brush elements, each brush element having an enlarged head connected to a proximal end of a bundle of bristles extending from the head to a distal end; wherein the head of a brush element is sized to be laterally received into one of the plurality of necked channels on the body of the brush tool with the bundle of bristles extending through the slot of the necked channel into which the head of the brush element is received.
 16. The brush tool of claim 15, further comprising: a channel closure member securable to the body of the brush tool proximal to the opening to obstruct the removal of the head of a brush element laterally received into the necked channel prior to securing the channel closure member to the body of the brush tool.
 17. The brush tool of claim 16, wherein the channel closure member is a threaded fastener.
 18. The brush tool of claim 16, wherein the channel closure member comprises a first sleeve half securable to a second sleeve half to surround a portion of the body of the brush tool adjacent to an opening of a necked channel in the exterior portion of the brush tool.
 19. The brush tool of claim 18, wherein the first sleeve half and the second sleeve half of the channel closure member each comprise lobes to provide a minimum separation distance between the center axis of the brush tool and an interior wall of a bore of a tubular string in which the brush tool is inserted.
 20. The brush tool of claim 18, wherein the first sleeve half and the second sleeve half of the channel closure member each comprise a necked channel in a radially outwardly disposed portion of the first sleeve half and the second sleeve half to laterally receive and retain brush elements. 